Abstract: A Novikov gearing comprising at least two gear elements the teeth of each element consisting of an addendum whose profile in the normal section is described by a convex curve, a dedendum and a fillet between the two. A portion of the fillet adjoining the addendum in the normal section has a convex profile with a radius of curvature smaller than a radius of curvature of the addendum.

Abstract: W-N gears of novel basic rack tooth profile designed to have at all times two points of meshing contact located in the same reference plane, one on an addendum arc of first tooth and the other on the dedendum arc of a second tooth neighboring the first tooth on its side opposite to the addendum arc, so that at the respective points of contacts the addendum and dedendum arcs have lines of radius aligned with each other. Such dual tooth contact enables much smoother and quieter gear operation, the points of contact proceeding in the direction of tooth trace.